Jet engines and other turbomachines employ turbines in a heated environment to produce power. Because of the design of such equipment, the power increases as the temperature in which the turbine operates increases. Consequently, it is beneficial to have components of the turbine which can withstand higher operating temperatures. Such components can include not only the turbine blades, but also the platform on which the turbine blades are supported.
Turbine blades are typically cooled to increase the temperature range in which they can effectively perform. In some turbines, the turbine blade platform can also be cooled, although it is usually incident to the cooling of the blade. Because the turbine blade has the largest exposed surface area and rotates at the extreme outer radius of the turbine's rotation, it is generally thought to experience the highest combination of stresses and temperature.
Because the turbine blade platform couples the turbine blade to other components of the turbine, the rotation of the turbine imparts stresses to the blade platform as well. Additionally, because the blade platform is exposed to the high temperature environment, it can experience failure modes where the combination of heat and stress cause plastic deformation. The combination of heat and stress experienced by the blade platform can be sufficient to cause plastic deformation even when the same conditions do not cause failure, through plastic deformation or otherwise, of the turbine blade.